Why my upload field is throwing error while attaching file?

Every few days our form stops accepting documents to upload. When a document is selected a red box appears around the button and doesn't attach. The work around is to remove and re-add the dropbox integration however it reappears every day or two. Any ideas?

We're sorry for this inconvenience.

Our developers did some changes on upload field which could cause that error. I did some necessary actions on your account so it should work fine now. I did several tests on your form and didn't encounter any error.

Please check and let us know if you face any problem.

Thank you!